A Fever in Salem: A New Interpretation of the New England Witch Trials

The author theorizes that the "demonic possessions" in Salem and other New England towns were caused by a form of encephalitis

Long Synopsis:

Between 1918 and the early 1930s, some five million people worldwide fell ill with a strange neurological disorder called encephalitis lethargica. Symptoms included convulsions, hallucinations, hyperactivity, deranged speech and behavior, coma, and in many cases, death. Carlson compares accounts of the 20th century pandemic with descriptions of the "demonic possession" reported in early New England. She builds a strong case that the bewitched persons in Salem and other New England towns may have been ill with encephalitis lethargica.